In bygone years wild discus were about all you could find in the aquarium shops. Then in the 80 's and 90 's "domestics" became very popular and wilds became hard to find. Now in the early 2000's "wilds" are very popular and easier to find. So the real answer is discus "sell" in cycles like other "products" and what "sells" is what is "stocked" in shops and is what we can find.